Help Diagnose Clutch Issue

[Oz22]

2018 Gen-2, 20,000 km on the clock
No soot in the pipes, no signs it's been abused, quite the opposite. Bike is stock from all appearances.

-- When I release the clutch after COLD starting the bike I hear a Wrrr Wrrr sound, Quite distinctive.
It goes away after 5 minutes of riding.
-- When I downshift to 3rd 2nd and 1st At Slow Speeds there is a slipping/clicking sound that goes for about 3 cycles, even with clutch out.
This too goes away after 5 minutes of riding? And it's not the back torque limiter, I know that sound.

-- I noticed that the clutch doesn't engage until right at the end of the lever's travel, a good bit further than on my other busa which is at 2/3 out
-- The clutch fluid reservoir is full.
-- The engine oil level is a bit high, perhaps an extra 200 or 300mL is in there but it's good new oil put in by the shop I suspect.

I've put about 500km on the bike since I bought it, never noticed these issues before but they could have been there? The noises made when downshifting while the motor was fully hot I would have missed as I usually ride out up the highway never backing off, only today did I do a slow crawl around town to investigate the clutch Wrrr sound. Like I said, it all goes away when the engine is hot, it's got me stumped? My only thought is to change the oil and see if that makes a difference. Perhaps the oil in there is too high a viscosity when cold? Or perhaps the clutch has been ridden???

 

[sixpack577]

I'de remove the clutch cover and check things out.
On the kickstand, you don't even have to drain the oil when you remove the cover.

 

[LC4CARL]

-- When I release the clutch after COLD starting the bike I hear a Wrrr Wrrr sound, Quite distinctive.

In neutral? Sound is “engine speed?” Goes away with clutch in?

-- When I downshift to 3rd 2nd and 1st At Slow Speeds there is a slipping/clicking sound that goes for about 3 cycles, even with clutch out.

Sound is “wheel speed?” Goes away with clutch in?

 

[LC4CARL]

Any change in noise accel vs decel?

 

[Oz22]

-- When I release the clutch after COLD starting the bike I hear a Wrrr Wrrr sound, Quite distinctive.

In neutral? Sound is “engine speed?” Goes away with clutch in?

-- When I downshift to 3rd 2nd and 1st At Slow Speeds there is a slipping/clicking sound that goes for about 3 cycles, even with clutch out.

Sound is “wheel speed?” Goes away with clutch in?

Yes with bike in neutral. What about the clutch lever engaging when it's nearly fully released?
Sound is “wheel speed?” Goes away with clutch in?
It goes away by itself after a second, as the bike slows down.

 

[Bumblebee]

Yes with bike in neutral. What about the clutch lever engaging when it's nearly fully released?
Sound is “wheel speed?” Goes away with clutch in?
It goes away by itself after a second, as the bike slows down.

These things make all kinds of crazy noises.......they are Suzukis afterall and that was part of their design......I find the very design of the fairing enhances the noises.

It's been a while since I rode my bike but it's clutch makes all kinds of rattling, whirring noises and I've had the clutch cover off and checked all the bolts, plate thickness, etc.....

I'd do what @sixpack577 says just for peace of mind, pop off the cover and check the bolts, I'd also ensure the oil is not overfilled, these things don't like that.

Other than that, I'd ride it like you stole it and enjoy it.......and don't over concentrate on noises unless they are really loud and distinctive like a connecting rod going through the block or something.....

 

[Oz22]

Cheers

 

[Bumblebee]

Cheers

Years ago a friend of mine had a GSXR with a dry clutch.....many people who didn't know Suzuki had a dry clutch bike would be really concerned that his engine was coming apart....he used to have fun with it while switching bike and not telling the recipient that it was a dry clutch.....they'd start it and think something was broken and shut if off right away looking at the clutch side....

Now that clutch was loud...I can see why Suzuki didn't continue with them...

 

[Dafeimao85]

2018 Gen-2, 20,000 km on the clock
No soot in the pipes, no signs it's been abused, quite the opposite. Bike is stock from all appearances.

-- When I release the clutch after COLD starting the bike I hear a Wrrr Wrrr sound, Quite distinctive.
It goes away after 5 minutes of riding.
-- When I downshift to 3rd 2nd and 1st At Slow Speeds there is a slipping/clicking sound that goes for about 3 cycles, even with clutch out.
This too goes away after 5 minutes of riding? And it's not the back torque limiter, I know that sound.

-- I noticed that the clutch doesn't engage until right at the end of the lever's travel, a good bit further than on my other busa which is at 2/3 out
-- The clutch fluid reservoir is full.
-- The engine oil level is a bit high, perhaps an extra 200 or 300mL is in there but it's good new oil put in by the shop I suspect.

I've put about 500km on the bike since I bought it, never noticed these issues before but they could have been there? The noises made when downshifting while the motor was fully hot I would have missed as I usually ride out up the highway never backing off, only today did I do a slow crawl around town to investigate the clutch Wrrr sound. Like I said, it all goes away when the engine is hot, it's got me stumped? My only thought is to change the oil and see if that makes a difference. Perhaps the oil in there is too high a viscosity when cold? Or perhaps the clutch has been ridden???

Hi Oz22,

Its the same on my busa and I am quite sure it's the back torque limiter that just started to be loose. Later part it will be more obvious.

U need a clutch slave support and brocks billet clutch mod.

Remove clutch cover and tighten it

Or u can ignore it...

 

[toncrell]

Hmm well I did the brocks billit on my 2020 because of nockingrattle noise and replaced clutch pack and I still have slight rattle sound at warm up but that it do do what Sixpack suggested see whatt if any bolts are lose just for piece of mind then check bolts every 3k miles or so gen 2 are nice but kinda noisy at warm up

 

[sixpack577]

And if you don't already know it, every new Suzuki gets it's own gremlin at the factory.
They constantly rattle and bang on things inside the engine.
It's like having your own dealer-tech inside...they don't really know what's going on, just beat on it with a wrench, and never find the problem, yet somehow...the engine lives on...

 

[Oz22]

Interestingly it turned out to have been the lever adjustment. I'd tinkered with it when I'd first got the bike, moved it in some. When I set the rotary knob at position 4 all the issues went away. By rights that should only effect the distance between the grip and lever when pulled, not the travel of the piston in the MC?

 

[Dafeimao85]

Interestingly it turned out to have been the lever adjustment. I'd tinkered with it when I'd first got the bike, moved it in some. When I set the rotary knob at position 4 all the issues went away. By rights that should only effect the distance between the grip and lever when pulled, not the travel of the piston in the MC?

Due to clutch switch. When the lever release it always went to the "default length"

The clicks however will be acting on the piston for the clutch before even the lever is being pull.

If I did not remb wrongly, 4 is being the default position or so call no additional pressure.

Using a numerical explanation will be like the following. Half clutch required 1 bar pressure while full clutch required 2 bar (the pressure is just a hypothesis for you to see the picture).

Position 4 with lever release, clutch box pressure = 0Bar

Position 4 with lever pulled, clutch box pressure = 2Bar

So when adjust to position 1 with lever release, clutch box pressure = 0.9 Bar the moment u pull a little bit u exceed the 1 bar to reach the half clutch. And while u pull to near half. Ur clutch piston is already fully compressed to 2 bar. Hence even if any more compression and also render it to full clutch.

Any bro can correct me if I am wrong but that was what I observe when I was replacing the mechanical piston.

If what you says is true then I suspect your clutch spring internally is losing tension hence resulting such effect. I do not recommend replacing the clutch spring if you are doing alot of city riding. Just live with position 4 until sympton appear again...

1 years ago, My clutch piston rubber torn and leak out brake fluid. And I had a itchy backside that instead of replacing the rubber seal. I proceed to replace the whole set. And my left wrist was forever angry at me and giving me soreness and pain to protest with the new spring.

 

[Dafeimao85]

Hi Oz22,

I apology. I think I am wrong.

I just check mine. It didn't compress at all. But I remb previously it was compressing the piston

Hence I suspect my current spring (about 4 month old) is providing the resistance. Hence the lever did not press on to the piston no matter what number I was at.

And 1 was being the furthest for the lever while 4 is the nearer to the handle. I measure each number result in about 2mm difference